@mukundakatta/timezone-mcp

MCP server for IANA timezone conversions. Real DST rules, real offsets via the built-in Intl.DateTimeFormat. No tzdata dependency, no native binary — Node ships the IANA database.

Tools

• convert_tz(instant, timezone) — UTC ISO → local in target tz
• now_in(timezone) — current local time in target tz
• tz_offset(instant, timezone) — UTC offset at that exact instant (DST-aware)

Why this exists

LLMs hallucinate timezone offsets and DST transition dates. They will confidently say "PST is UTC-8" in summer (it's PDT, UTC-7). They get India's +5:30 half-hour offset wrong. Routing through Intl.DateTimeFormat returns whatever the actual IANA rules say.

Install — Claude Desktop

{
  "mcpServers": {
    "timezone": { "command": "npx", "args": ["-y", "@mukundakatta/timezone-mcp"] }
  }
}

Same shape for Cursor / Cline / Windsurf / Zed.

License

MIT OR Apache-2.0.